Transformers change the turns per effective coil on the high voltage side of transformers through the switching from one tap to another tap to realize voltage adjustment. The on-load tap-changing switch switches the load current via a changing switch, and the high-speed mechanism is the power source of changing switch. At present, the high-speed mechanism mainly adopts a spring energy-releasing unit, but the reliability of spring is poor, and once the main spring is damaged, the whole will break down; as the use time extends, the elasticity of spring will gradually become poor or the spring will break off, which will cause serious consequences.